The present invention generally relates to a position detecting apparatus which is provided with a detecting face so as to detect the positions of points specified on the detection face thereof.
Because of spread of planar displays such as liquid crystal, EL (electro.multidot.luminance) and so on, a display apparatus which is adapted to effect the positional detection on the display has increased in number. Position detecting apparatuses to be used for such display apparatuses are used to indicate the positions on the display face, to effect the recognition inputs of hand written letters, or the like.
Generally the resolution of the position detecting apparatus to be used for indicating positions on the display face is not required enough to be demanded in the recognition inputs of the hand-written letters.
FIGS. 6(a), 6(b) are views showing the conventional position detecting apparatus. The FIG. 6(a) thereof shows a position detecting apparatus of rough resolution and the FIG. 6(b) thereof a position detecting apparatus of close resolution.
The position detecting system of the position detecting apparatus has various ones such as electromagnetic induction system, pressure sensing system, electrostatic system and so on. As they are well known in art and have no direct relation with the present utility mode, sense lines only have only to be drawn.
The position detecting apparatus of FIG. 6(a) is suitable for the position detection of the large area. It is used as a pointing device with, for example, the position detecting apparatus being engaged on the liquid crystal surface face. The position detecting apparatus of FIG. 6(b) is suitable for the position detection of the comparatively small area. It is used for the position detection of higher precision. The position detecting apparatus is often used for, for example, on line letter recognition and so on.
The above described conventional position detecting apparatus has the following defects.
Although the position detecting apparatus of the rough resolution in FIG. 6(a) is suitable for the position detection of the large area, it is difficult to detect the minute positions as in the letter recognition. Although the position detecting apparatus of the fine resolution in FIG. 6(b) is suitable for the detection of the minute position, a lot of sense lines are required, because the area becomes larger to effect the position detection of the large area. Therefore, the highly advanced manufacturing art is required, with a problem that the position detecting apparatus becomes higher in cost.